Solyndra executives plead the 5th

Executives from the bankrupt solar panel maker Solyndra refuse to answer questions surrounding the $535 loan guarantee they received from the government.

NEW YORK (CNNMoney) -- Lawmakers at a hearing on Capitol Hill Friday pledged to press ahead with their investigation into bankrupt solar panel maker Solyndra, despite silence from company executives who invoked the fifth amendment.

"Was all the information they submitted complete, what did they know, and when did they know it," Rep. Cliff Stearns, the Florida republican who heads the House Subcommittee on Oversight and Investigations, said during a hearing on the matter. "We will get to the bottom of this."

Solyndra executives Brian Harrison and W.G. Stover were present at the hearing. They maintained no wrongdoing took place at the company, but repeatedly refused to answer any questions on the advice of their attorney.

Solyndra declared bankruptcy last month. The company received a $535 million loan guarantee from the Energy Department in 2009 under a program started by President Bush and expanded as part of the Obama's administration's stimulus effort.

Agents from the FBI and the Energy Department's inspector general's office raided the company's office earlier this month. Neither agency would comment on the nature of the raid, but the inspector general typically investigates cases of wrongdoing at the Energy Department and the entities it does business with.

Lawmakers on the oversight committee are conducting their own investigation. They want to know why one month before it filed for bankruptcy the executives told them and DOE that the company was doing just fine.

Solyndra's loan guarantee did not come in one chunk, but was handed out in stages after meeting milestones set by the DOE. The company ultimately drew down $527 million of the $535 million offered.

Lawmakers also want to know if the Energy Department rushed out the loan guarantee, either to jump-start the stimulus program or due to political pressure.

"Was the White House duped by Solyndra, or did they ignore the information to put green energy in a better light, or for more onerous reasons," asked Nebraska Rep. Lee Terry, a Republican.

One of Solyndra's main financial backers was also a big fundraiser for Obama in 2008 and lawmakers have questioned whether that played a part in the loan guarantee.

Lawmakers wanted to know the nature of several meetings between the Solyndra executives and White House aids over the last couple of years.

"On advice of my counsel, I invoke the privilege afforded by the fifth amendment to the U.S. Constitution, and I respectfully decline to answer any questions," was the response from each executive to every question.

Energy Department officials maintain there was no inappropriate political pressure that factored into the loan guarantee, noting that the company received major financial support from the private sector as well, including from an investment fund run by noted Republican donors.

Critics hold it up as an example of why the government shouldn't be funding start-up companies, especially ones with unproven technology like certain forms of renewable energy. If the technologies really do work, they say, they will attract funding from the private sector.

Supporters say government support for clean energy is essential if the nation is going to move away from fossil fuels and compete with countries like China, which lavishes support on its own renewable energy industry.